Wind turbine plants typically include a tower and a rotor/turbine mounted on top of the tower. The rotor may include one or more blades that rotate about a center point when in the presence of wind. The rotor motion may then be converted to electrical or other energy by known means.
Many wind turbine towers include electrical machinery/equipment within them, such as for converting rotational energy from the rotor into electrical energy. The electrical machinery may include, for example, converter electronics, voltage switch gear and a transformer. In some cases these components or equipment are supported by a separate installation unit, and mounted in the tower by lowering the unit into the tower from the top thereof, to become surrounded by the tower.
Typically, as the installation unit is being lowered, technicians is located on internal tower levels to ensure that the unit does not contact and, thus, damage the tower wall and also to correctly align the installation unit with supporting abutments or projections deeper inside the tower. Because wind towers are typically located in areas having frequent wind currents, it is common for wind gusts to move the installation unit as it is being lowered. This could lead to injury of the personnel if contacted by the installation unit.